Leakage-resistant tissue treatment apparatus and methods of using same

ABSTRACT

Apparatus and methods for treating skin conditions that deliver high frequency energy to a patient&#39;s tissue. The apparatus has a treatment tip configured to be removably coupled with a handpiece and a conduit inside the handpiece. The treatment tip includes an electrode configured to deliver the high frequency energy to a region of the tissue, a channel for circulating heat transfer fluid proximate to the electrode, and an inlet passage to the channel. The conduit includes a tubular sidewall with a lumen used to transfer the heat transfer fluid from the handpiece to the inlet passage of the treatment tip. When the treatment tip is coupled to the handpiece, a septum covering the inlet passage is configured to be pierced by the conduit to define an opening for coupling the conduit with the inlet passage. When the treatment tip is removed from the handpiece, the septum substantially seals the opening.

FIELD OF THE INVENTION

The invention generally relates to apparatus and methods for treatingtissue with high frequency energy and, more particularly, relates totreatment apparatus and methods for treating tissue with high frequencyenergy that include liquid-mediated tissue cooling and leakage controlmechanisms for the heat transfer fluid used in the liquid-mediatedtissue cooling.

BACKGROUND OF THE INVENTION

Energy delivery devices that can non-invasively treat tissue areextensively used to therapeutically treat numerous diverse skinconditions. Among other uses, non-invasive energy delivery devices maybe used to tighten loose skin to make a patient appear younger, removeskin spots or hair, or kill bacteria. Such non-invasive energy deliverydevices emit electromagnetic energy in different regions of theelectromagnetic spectrum for tissue treatment.

High frequency treatment devices, such as radio-frequency (RF)-baseddevices, may be used to treat skin tissue non-ablatively andnon-invasively by passing high frequency energy through a surface of theskin to underlying tissue, while actively cooling the skin to preventdamage to a region of the tissue near the skin surface. The highfrequency energy heats the tissue beneath the cooled region to atemperature sufficient to denature collagen, which causes the collagento contract and shrink and, thereby, tighten the treated tissue.Treatment with high frequency energy also causes a mild inflammation.The inflammatory response of the treated tissue causes new collagen tobe generated over time (between three days and six months followingtreatment), which results in further tissue contraction.

Modern high frequency treatment devices employ a handpiece, a treatmenttip coupled with the handpiece, and a high frequency generator connectedwith electrodes in the treatment tip by the handpiece. Conventionalelectrodes consist of a pattern of metallic features carried on aflexible electrically insulating substrate, such as a thin film ofpolyimide. The substrate contacts the patient's skin surface duringtreatment. The temperature of the treatment tip, which is measured bytemperature sensors carried on the treatment tip, is correlated with thetemperature of the patient's skin.

Treatment tips are frequently intended for single patient use and,therefore, non-reusable. As a result, the disposable treatment tips aredesigned to be temporarily installed onto the nose of the reusablehandpiece. Upon installation onto the handpiece nose, one or morelatches lock the treatment tip in the proper position. After theconclusion of the patient treatment, the doctor or treatment technicianunlatches the treatment tip and removes it from the handpiece to bediscarded.

The treatment tip is cooled with a heat transfer fluid for the purposeof cooling the tissue region proximate to the skin surface that is in acontacting relationship with the substrate carrying the one or moreelectrodes. The superficial cooling protects outer layers of tissue andregulates the treatment depth. One approach for supplying heat transferfluid to the treatment tip is a closed-loop cooling system thatcirculates the heat transfer fluid through the treatment tip. When thetreatment tip and handpiece are united together, pathways areestablished between the treatment tip and handpiece for the transfer offluid to and the draining of fluid from the treatment tip.

When the treatment tip is initially united with the handpiece, thepathways from the handpiece to the treatment tip should be free ofleakage. The separate pathways permit the heat transfer fluid to flowfrom the handpiece to the treatment tip and then return from thetreatment tip back to the handpiece after circulation through thetreatment tip. When the treatment tip is separated from the handpiecefollowing a patient treatment, the continuity of the pathways issevered. The portions of the severed pathways in the handpiece areunblocked, which may permit the heat transfer fluid to leak or drip fromthe handpiece. In addition, the portions of the severed pathways in thetreatment tip are also unblocked, which may cause heat transfer fluid toleak from the treatment tip before disposal.

What is needed, therefore, are apparatus and methods for controlling theescape of heat transfer fluid from the treatment tip when the treatmenttip is removed from the handpiece.

SUMMARY OF THE INVENTION

The invention is generally directed to treatment apparatus and methodsthat deliver high frequency energy to tissue underlying a skin surfaceduring non-invasive tissue treatments. The treatment apparatus deliversa fluid, such as a heat transfer fluid, from a handpiece to a treatmenttip. The fluid may be returned from the treatment tip to the handpieceto define closed loop circulation.

In one embodiment, the apparatus includes a treatment tip configured tobe removably coupled with a handpiece and a conduit inside thehandpiece. The treatment tip includes an electrode configured to deliverthe high frequency energy to a region of the tissue, a channel forcirculating heat transfer fluid proximate to the electrode, and an inletpassage to the channel. The conduit includes a tubular sidewall with alumen configured to be coupled with the inlet passage for transferringthe heat transfer fluid from the handpiece to the inlet passage of thetreatment tip. A septum covers the inlet passage and, when the treatmenttip is coupled to the handpiece, is configured to be pierced by theconduit to define an opening for coupling the first conduit with theinlet passage. When the treatment tip is removed from the handpiece todecouple the conduit from the inlet passage, the septum substantiallyseals the first opening.

In another embodiment, a method is provided for operating a tissuetreatment apparatus to treat tissue located beneath a skin surface withhigh frequency energy delivered from an electrode. The method includesattaching a treatment tip carrying the electrode to a handpiece toestablish a fluid connection between a lumen of a conduit in thehandpiece and an inlet passage in the treatment tip. When attaching thetreatment tip to the handpiece to establish the fluid connection, theconduit pierces a septum to define an opening permitting the conduit tobe coupled in fluid communication with the inlet passage. The methodfurther includes transferring heat transfer fluid through the lumen ofthe conduit to the treatment tip, and delivering the high frequencyenergy from the electrode to a region of the tissue to perform a tissuetreatment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of a treatment system with a handpiece, atreatment tip, and a console in accordance with an embodiment of theinvention

FIG. 2 is a diagrammatic view of the handpiece, treatment tip, andconsole of FIG. 1 showing a closed-loop cooling system of the treatmentsystem.

FIG. 3 is a rear view of the assembled treatment tip taken generallyalong line 3-3 in FIG. 2 showing the electrode and temperature sensors.

FIG. 4 is an exploded view of the treatment tip of FIG. 2 in which thetreatment electrode is shown in an unfolded condition.

FIG. 5 is a front perspective view of a manifold body located inside thetreatment tip of FIG. 4.

FIG. 6 is a rear perspective view of the manifold body of FIG. 5.

FIG. 7 is an enlarged cross-sectional view of a circled region in FIG.2.

FIG. 8 is a perspective view of the handpiece and treatment tip of FIG.2 in which the treatment tip is shown separated from the handpiece.

FIG. 9 is an enlarged cross-sectional view similar to FIG. 7 in whichthe treatment tip is shown separated from the handpiece.

DETAILED DESCRIPTION

With reference to FIGS. 1-4, a treatment apparatus 10 includes ahandpiece 12, a treatment tip 14 coupled in a removable and releasablemanner with the handpiece 12, a console generally indicated by referencenumeral 16, and a system controller 18. The system controller 18, whichis incorporated into the console 16, controls the global operation ofthe different individual components of the treatment apparatus 10. Underthe control of the system controller 18 and an operator's interactionwith the system controller 18 at the console 16, the treatment apparatus10 is adapted to selectively deliver electromagnetic energy in a highfrequency band of the electromagnetic spectrum, such as theradiofrequency (RF) band to non-invasively heat a region of a patient'stissue to a targeted temperature range. The elevation in temperature mayproduce a desired treatment, such as removing or reducing wrinkles andotherwise tightening the skin to thereby improve the appearance of apatient 20 receiving the treatment. In alternative embodiments, thetreatment apparatus 10 may be configured to deliver energy in theinfrared band, microwave band, or another high frequency band of theelectromagnetic spectrum, rather than energy in the RF band, to thepatient's tissue.

The treatment tip 14 carries an energy delivery member in therepresentative form of a treatment electrode 22. The treatment electrode22 is electrically coupled by a set of conductors 21 with a generator 38configured to generate the electromagnetic energy used in the patient'streatment. In a representative embodiment, the treatment electrode 22may have the form of a region 26 of an electrical conductor carried onan electrically-insulating substrate 28 composed of a dielectricmaterial. In one embodiment, the substrate 28 may comprise a thinflexible base polymer film carrying the conductor region 26 and thinconductive (e.g., copper) traces or leads 24 on the substrate 28 thatelectrically couple the conductor region 26 with contact pads 25. Thebase polymer film may be, for example, polyimide or another materialwith a relatively high electrical resistivity and a relatively highthermal conductivity. The conductive leads 24 may contain copper oranother material with a relatively high electrical conductivity. Insteadof the representative solid conductor region 26, the conductor region 26of treatment electrode 22 may include voids or holes unfilled by theconductor to provide a perforated appearance or, alternatively, may besegmented into plural individual electrodes that can be individuallypowered by the generator 38.

In one specific embodiment, the treatment electrode 22 may comprise aflex circuit in which the substrate 28 consists of a base polymer filmand the conductor region 26 consists of a patterned conductive (i.e.,copper) foil laminated to the base polymer film. In another specificembodiment, the treatment electrode 22 may comprise a flex circuit inwhich the conductor region 26 consists of patterned conductive (i.e.,copper) metallization layers directly deposited the base polymer filmby, for example, a vacuum deposition technique, such as sputterdeposition. In each instance, the base polymer film constitutingsubstrate 28 may be replaced by another non-conductive dielectricmaterial and the conductive metallization layers or foil constitutingthe conductor region 26 may contain copper. Flex circuits, which arecommonly used for flexible and high-density electronic interconnectionapplications, have a conventional construction understood by a personhaving ordinary skill in the art.

The substrate 28 includes a contact side 32 that is placed into contactwith the skin surface of the patient 20 during treatment and anon-contact side 34 that is opposite to the contact side 32. Theconductor region 26 of the treatment electrode 22 is physically carriedon non-contact side 34 of the substrate 28. In the representativearrangement, the substrate 28 is interposed between the conductor region26 and the treated tissue such that, during the non-invasive tissuetreatment, electromagnetic energy is transmitted from the conductorregion 26 through the thickness of the substrate 28 by capacitivelycoupling with the tissue of the patient 20.

When the treatment tip 14 is physically engaged with the handpiece 12,the contact pads 25 face toward the handpiece 12 and are electricallycoupled with electrical contacts (not shown), such as pogo pin contacts,inside the handpiece 12. These electrical contacts are electricallycoupled with insulated and shielded conductors 21 that extend exteriorlyof the handpiece 12 to a generator 38 at the console 16. The generator38, which has the form of a high frequency power supply, is equippedwith an electrical circuit (not shown) operative to generate highfrequency electrical current, typically in the radio-frequency (RF)region of the electromagnetic spectrum. The operating frequency ofgenerator 38 may advantageously be in the range of several hundred kHzto about twenty (20) MHz to impart a therapeutic effect to treat targettissue beneath a patient's skin surface. The circuit in the generator 38converts a line voltage into drive signals having an energy content andduty cycle appropriate for the amount of power and the mode of operationthat have been selected by the clinician, as understood by a personhaving ordinary skill in the art. In one embodiment, the generator 38 isa 400-watt, 6.78 MHz high frequency generator.

A non-therapeutic passive or return electrode 40, which is electricallycoupled with the generator 38, is physically attached to a site on thebody surface of the patient 20, such as the patient's lower back. Duringtreatment, high frequency current flows from the treatment electrode 22through the treated tissue and the intervening bulk of the patient 20 tothe return electrode 40 and then through conductors inside a returncable 41 to define a closed circuit or current path 42. Because of therelatively large surface area of the return electrode 40 in contact withthe patient 20, the current density flowing from the patient 20 to thereturn electrode 40 is relatively low in comparison with the currentdensity flowing from the treatment electrode 22 to the patient 20. As aresult, the return electrode 40 is non-therapeutic because negligibleheating is produced at its attachment site to the patient 20. Highfrequency electrical current flowing between the treatment electrode 22and the patient 20 is maximized at the skin surface and underlyingtissue region adjacent to the treatment electrode 22 and, therefore,delivers a therapeutic effect to the tissue region near the treatmentsite.

As best shown in FIG. 3, the treatment tip 14 includes temperaturesensors 44, such as thermistors or thermocouples, that are located onthe non-contact side 34 of the substrate 28 that is not in contact withthe patient's skin surface. Typically, the temperature sensors 44 arearranged about the perimeter of the conductor region 26 of the treatmentelectrode 22. Temperature sensors 44 are constructed to detect thetemperature of the treatment electrode 22 and/or treatment tip 14, whichmay be representative of the temperature of the treated tissue. Each ofthe temperature sensors 44 is electrically coupled by conductive leads46 with one or more of the contact pads 25, which are used to supplydirect current (DC) voltages from the system controller 18 through theshielded conductors 21 to the temperature sensors 44.

With continued reference to FIGS. 1-4, the system controller 18regulates the power delivered from the generator 38 to the treatmentelectrode 22 and otherwise controls and supervises the operationalparameters of the treatment apparatus 10. The system controller 18 mayinclude user input devices to, for example, adjust the applied voltagelevel of generator 38. The system controller 18 includes a processor,which may be any suitable conventional microprocessor, microcontrolleror digital signal processor, executing software to implement controlalgorithms for the operation of the generator 38. System controller 18,which may also include a nonvolatile memory (not shown) containingprogrammed instructions for the processor, may be optionally integratedinto the generator 38. System controller 18 may also communicate, forexample, with a nonvolatile memory carried by the handpiece 12 or by thetreatment tip 14. The system controller 18 also includes circuitry forsupplying the DC voltages and circuitry that relates changes in the DCvoltages to the temperature detected by the temperature sensors 44, aswell as temperature sensors 90 and 88.

With specific reference to FIG. 8, the handpiece 12 is constructed froma body 48 and a cover 50 that is assembled with conventional fastenerswith the body 48. The assembled handpiece 12 has a smoothly contouredshape suitable for manipulation by a clinician to maneuver the treatmenttip 14 and treatment electrode 22 to a location proximate to the skinsurface and, typically, in a contacting relationship with the skinsurface. An activation button 36, which is accessible to the clinicianfrom the exterior of the handpiece 12, is depressed for closing a switchthat energizes the treatment electrode 22 and, thereby, delivers highfrequency energy over a short delivery cycle to treat the target tissue.Releasing the activation button 36 opens the switch to discontinue thedelivery of high frequency energy to the patient's skin surface andunderlying tissue. After the treatment of one site is concluded, thehandpiece 12 is manipulated to position the treatment tip 14 near adifferent site on the skin surface for another delivery cycle of highfrequency energy delivery to the patient's tissue.

With reference to FIGS. 4-6, the treatment tip 14 includes a rigid outershell 52, a rear cover 54 that is coupled with an open rearward end ofthe outer shell 52, and a manifold body 55 disposed inside an enclosureor housing inside the outer shell 52. A portion of the substrate 28overlying the conductor region 26 of the treatment electrode 22 isexposed through a window 56 defined in a forward open end of the outershell 52. The substrate 28 is wrapped or folded about the manifold body55. A hooked prong 58 (FIGS. 7, 9), which projects from the rear cover54, is captured by a lip on the handpiece 12 during installation of thetreatment tip 14.

As best shown in FIGS. 4 and 5, the manifold body 55, which may beformed from an injection molded polymer resin, includes a front section60, a stem 62 projecting rearwardly from the front section 60, and ribs64 on the stem 62 used to position the manifold body 55 inside the outershell 52. The front section 60 of the manifold body 55 includes achannel 66 that, in the assembly constituting treatment tip 14,underlines the conductor region 26 of the treatment electrode 22. Theshape of the front section 60 corresponds with the shape of the window56 in the outer shell 52. The substrate 28 of the treatment electrode 22is bonded with a rim 68 of the manifold body 55 to provide a fluid sealthat confines heat transfer fluid 94 flowing in the channel 66. The areainside the rim 68 is approximately equal to the area of the conductorregion 26 of treatment electrode 22. Channel 66 includes convolutionsthat are configured to optimize the residence time of the heat transferfluid 94 in channel 66, which may in turn optimize the heat transferbetween the heat transfer fluid 94 and the treatment electrode 22.

An inlet bore or passage 70 and an outlet bore or passage 72 extendthrough the stem 62 of the manifold body 55. The inlet passage 70 andoutlet passage 72 are rearwardly accessible through an oval-shaped slot74 defined in the rear cover 54. The inlet passage 70 intersects thechannel 66 at an inlet 76 to the channel 66 and the outlet passage 72intersects the channel 66 at an outlet 78 from the channel 66. Thechannel 66 is split into two channel sections 80, 82 so that fluid flowin the channel 66 diverges away in two separate streams from the inlet76 and converges together to flow into the outlet 78. Fluid pressurecauses the heat transfer fluid 94 to flow from the inlet 76 through thetwo channel sections 80, 82 to the outlet 78 and into the outlet passage72.

With reference to FIGS. 2 and 4-6, fluid connections are establishedwith the inlet passage 70 and the outlet passage 72 to establish theclosed circulation loop and permit fluid flow to the channel 66 in themanifold body 55 when the treatment tip 14 is mated with the handpiece12. Specifically, the inlet passage 70 to the manifold body 55 iscoupled with a supply line 86 in the form of an inlet conduit or tube.The outlet passage 72 from the manifold body 55 is coupled with a returnline 84 in the form of a fluid conduit or tube. The return line 84 andthe supply lines 86 extend out of the handpiece 12 and are routed to theconsole 16. Structure facilitating the establishment of fluid-tightconnections is described in detail hereinbelow.

With reference to FIG. 2, the treatment apparatus 10 is equipped with aclosed loop cooling system that includes the manifold body 55 locatedinside the treatment tip 14. The closed loop cooling system furtherincludes a reservoir 96 holding a volume of a heat transfer fluid 94 anda pump 98, which may be a diaphragm pump, that continuously pumps astream of the heat transfer fluid 94 from an outlet of the reservoir 96through the supply line 86 to the manifold body 55 in the treatment tip14. The manifold body 55 is coupled in fluid communication with thereservoir 96 by the return line 84. The return line 84 conveys the heattransfer fluid 94 from the treatment tip 14 back to the reservoir 96 tocomplete the circulation loop.

Heat generated in the treatment tip 14 by energy delivery from thetreatment electrode 22 and heat transferred from the patient's skin andan underlying depth of heated tissue is conducted through the substrate28 and treatment electrode 22. The heat is absorbed by the circulatingheat transfer fluid 94 in the channel 66 of the manifold body 55, whichlowers the temperature of the treatment electrode 22 and substrate 28and, thereby, cools the patient's skin and the underlying depth ofheated tissue. The contact cooling, at the least, assists in regulatingthe depth over which the tissue is heated to a therapeutic temperatureby the delivered electromagnetic energy.

The heat transfer fluid 94 stored in the reservoir 96 is chilled by aseparate circulation loop 101 that pumps heat transfer fluid 94 from thereservoir 96 through separate supply and return lines to a coldplate102. A pump 100, which may be a centrifugal pump, pumps the heattransfer fluid 94 under pressure from the reservoir 96 to the coldplate102. In a representative embodiment, the coldplate 102 may be aliquid-to-air heat exchanger that includes a liquid heat sink with achannel (not shown) for circulating the heat transfer fluid 94, athermoelectric module (not shown), and an air-cooled heat sink (notshown).

A temperature controller 104 inside the console 16 is electricallycoupled with the coldplate 102 and is also electrically coupled with thesystem controller 18. The system controller 18, which is electricallycoupled with a temperature sensor 88 used to measure the heat transferfluid temperature in the reservoir 96, supplies temperature controlsignals to the temperature controller 104 in response to the measuredheat transfer fluid temperature. Under the feedback control, thetemperature controller 104 reacts to the control temperaturecommunicated from the temperature sensor 88 to control the operation ofthe coldplate 102 and, thereby, regulate the temperature of the heattransfer fluid 94 in the reservoir 96.

With reference to FIGS. 4 and 7-9, the handpiece 12 includes a pair ofrigid tubes 110, 112 with respective tips 114, 116 that projectoutwardly from a flow part 118. The flow part 118 conceals the portionsof the rigid tubes 110, 112 located inside the handpiece 12. The rigidtubes 110, 112 extend through respective openings penetrating throughthe flow part 118 and have lumens 111, 113 that are respectively coupledinside the handpiece 12 with a pair of flexible conduits or lines 120,122.

A flow control valve in the representative form of a pinch valve,generally indicated by reference numeral 124, is located inside thehandpiece 12. The pinch valve 124 includes a pin 126, a movable memberin the form of a ram or plunger 128 that is mechanically coupled withthe pin 126 to form an assembly, a stationary member in the form of ananvil body 130 on the flow part 118, and an actuator in therepresentative form of a coil spring 132 that is configured to apply abiasing force to the plunger 128. A forward end 125 of the pin 126 iscentrally located between the tips 114, 116 of the rigid tubes 110, 112and, inside the handpiece 12, the remainder of the pin 126 is centrallylocated between the rigid tubes 110, 112 and the flexible lines 120,122. The anvil body 130 includes a spaced-apart pair of contouredcontact or pinch surfaces 134, 136. One of the flexible lines 120 islocated between a contact or pinch surface 138 of plunger 128 and pinchsurface 134 on the anvil body 130. The other flexible line 122 islocated between a contact or pinch surface 140 of plunger 128 and pinchsurface 136 on the anvil body 130.

The pinch valve 124 has a first closed position (FIGS. 8, 9) in whichthe flexible lines 120, 122 are respectively compressed between thepinch surfaces 134, 136 on anvil body 130 and the pinch surfaces 138,140 on plunger 128. The material forming the flexible lines 120, 122 issufficiently compliant to the compressive force or pressure from thepinching action so that the respective sidewalls collapse inwardly tototally or partially occlude a lumen 142 of flexible line 120 and alumen 144 of flexible line 122. In a closed position, heat transferfluid 94 is substantially or completely occluded by the pinch valve 124from flowing through the flexible lines 120, 122 to an extent sufficientto reduce or eliminate fluid leakage from the outlets of the rigid tubes110, 112. The closed position occurs when the treatment tip 14 isremoved from the handpiece 12.

The rigid tubes 110, 112, which are relatively short in comparison withthe flexible lines 120, 122, may be formed from a stainless steel. Incontrast, the flexible lines 120, 122 are formed from a polymer or anelastomeric material, like a silicone rubber, that is significantly moreflexible (has a greater ability to bend) than the material forming therigid tubes 110, 112. In other words, the flexible lines 120, 122 areformed from a material having a significantly lower shear modulus ormodulus of rigidity than a material forming the rigid tubes 110, 112.

The flexible lines 120, 122 distort slightly to permit the ends of theflexible lines 120, 122 to be slipped over respective lengths of therigid tubes 110, 112 and grip the rearward ends of the rigid tubes 110,112 after installation to provide a fluid-tight seal. Flexible line 120has a tubular sidewall 121 composed of a material with sufficientflexibility to at least partially occlude the enclosed lumen 142 byreducing the cross-sectional area for fluid flow when a compressiveforce is applied between pinch surface 138 of plunger 128 and pinchsurface 134 on the anvil body 130 of the pinch valve 124. The occlusion,which controls the flow of fluid through the lumen 142, causesdeformation that at least partially collapses the lumen 142. Similarly,flexible line 122 has a tubular sidewall 123 composed of a material withsufficient flexibility to at least partially occlude the enclosed lumen144 by reducing the cross-sectional area for fluid flow when acompressive force is applied between pinch surface 140 of plunger 128and pinch surface 136 on the anvil body 130 of the pinch valve 124. Theocclusion, which controls the flow of fluid through the lumen 144,causes deformation that at least partially collapses the lumen 144. Thedeformation of the tubular sidewalls 121, 123 is primarily elastic inthat the tubular sidewalls 121, 123 return to substantially theiroriginal shape and cross-sectional area when the compressive force isremoved.

In the closed position, respective columns of residual heat transferfluid 94 may remain inside the rigid tubes 110, 112, as well as insidethe portion of the flexible lines 120, 122 between the pinch surfaces134, 136, 138, 140 and the rigid tubes 110, 112. Although not wishing tobe bound by theory, the columns may remain static and resident insidethe handpiece 12 until another treatment tip 14 is installed, whichimplies that the effective flow rate is zero milliliters per minute.

The pinch valve 124 has an open position (FIGS. 4, 7) in which the pinchsurfaces 138, 140 on plunger 128 are separated from the pinch surfaces134, 136 on anvil body 130 so that the flexible lines 120, 122 are notcompressed therebetween. In the open position, heat transfer fluid 94 ispermitted to flow at a given flow rate through the lumen 142 of flexibleline 120 to the manifold body 55 inside the treatment tip 14 and to flowthrough the lumen 144 of flexible line 122 out of the manifold body 55.The second position is created when the treatment tip 14 is installed onthe nose of the handpiece 12. When the compressive force or pressureapplied by the pinch surfaces 134, 136, 138, 140 is removed from theflexible lines 120, 122, the sidewalls of the flexible lines 120, 122recover approximately to their initial non-compressed state and providea given flow rate of the heat transfer fluid 94 to the treatment tip 14.

The inlet passage 70 in the stem 62 of the manifold body 55 has atubular section 152 truncated to terminate at an open end. Similarly,the outlet passage 72 in the stem 62 of the manifold body 55 has atubular section 154 terminating at another end. The tubular sections152, 154 are raised above the surrounding portions of the manifold body55 and project toward the handpiece 12 when the treatment tip 14 isinstalled to establish a fluid interface with the handpiece 12.

The tubular sections 152, 154 intersect to define a central activationarm 146. A contact block 145 is located on an opposite side of a septum150 from the activation arm 146. The contact block 145 and activationarm 146 participate in providing the open position when the treatmenttip 14 is installed in the nose of the handpiece 12, as depicted inFIGS. 4 and 7. Specifically, the activation arm 146 and contact block145, which are self-aligned, are also aligned with the pin 126 of thepinch valve 124. During installation to mate the treatment tip 14 withthe handpiece 12, the contact block 145 contacts a portion of the pin126. The activation arm 146 prevents the septum 150 from deflecting as areinforcement force is applied by the pin 126 to the contact block 145.The pin 126 and the plunger 128 are pushed by the activation arm 146 andcontact block 145 in a direction away from the treatment tip 14 andagainst the biasing force applied by the coil spring 132 to the plunger128 that resists motion toward the open position. The coil spring 132compresses so as to store biasing energy for use in applying a forceurging the pinch valve 124 to re-establish the first closed position(FIGS. 8, 9).

The coil spring 132 must apply a spring force to the plunger 128 that issufficient to compress the flexible lines 120, 122 and place the pinchvalve 124 in its closed position. However, the coil spring 132 mustreadily yield to permit installation of the treatment tip 14 andestablish the open position of pinch valve 124. Hence, the properties ofthe coil spring 132 should be selected to apply an appropriate springforce to the plunger 128.

The flexible lines 120, 122 isolate the heat transfer fluid 94 insidethe closed-loop cooling from the components of the pinch valve 124,which prevents contact between the components and the heat transferfluid 94. The tubing constituting flexible lines 120, 122 is alwaysimposed between the heat transfer fluid 94 and the components of thepinch valve 124, which may be beneficial, for example, if contact withthe heat transfer fluid 94 is capable of corroding the components of thepinch valve 124. This benefit means that the materials for thecomponents of the pinch valve 124 are not constrained to be corrosionresistant to the heat transfer fluid 94 as these components are notwetted by the heat transfer fluid 94. Fluid transfer can be effectivelycontrolled by the pinch valve 124 without concerns raised by fluidwetting of the valve components.

The septum 150, which is best shown in FIGS. 4 and 9, covers the openend 151 of the inlet passage 70 and the open end 153 of the outletpassage 72. During installation, the tips 114, 116 of the rigid tubes110, 112 apply a force that is substantially perpendicular to the planeof the septum 150. The applied force pierces the septum 150 to defineopenings 115, 117 that place the lumens 111, 113 of the rigid tubes 110,112 in fluid communication with the inlet and outlet passages 70, 72,respectively. These temporary fluid connections, which are formed whenthe treatment tip 14 is attached to the handpiece 12, complete theclosed circulation loop. When the treatment tip 14 is separated from thehandpiece 12, the septum 150 heals to close or substantially close theopenings 115, 117 so that residual heat transfer fluid 94 remaining inthe detached treatment tip 14 is blocked from escape.

When the treatment tip 14 is coupled with the handpiece 12, the tip 114of the rigid tube 110 protrudes through the opening 115 in the septum150 and projects into an enlarged region at the entrance to the inletpassage 72. Similarly, the tip 116 of the rigid tube 112 protrudesthrough the opening 117 in the septum 150 and projects into an enlargedregion at the entrance to the outlet passage 70. The material of septum150 about the openings 115, 117 grips the exterior of the tips 114, 116so that fluid-tight connections are established.

In one embodiment, the septum 150 is a thin membrane composed of anelastomeric material characterized by properties that permit the tips114, 116 of the rigid tubes 110, 112 to pierce the septum 150 and, uponwithdrawal of the tips 114, 116, permit the membrane to heal or closethe openings 115, 117 so that residual heat transfer fluid 94 isretained in the treatment tip 14. Specifically, the elastomericmaterial, when pierced at spaced apart locations by the tips 114, 116 ofthe rigid tubes 110, 112, near the edges of openings 115, 117 compressesslightly and grips about the outer diameter of each of the rigid tubes110, 112 with a radial reaction force. When the tips 114, 116 of therigid tubes 110, 112 are withdrawn, the compressed elastomeric materialforces the openings 115, 117 to close. Starter openings 156, 158 areprovided in the septum 150 at the approximate locations at which theseptum 150 is pierced by the tips 114, 116 of the rigid tubes 110, 112.The starter openings 156, 158 function to permit the tips 114, 116 toinitiate penetration through the septum 150 and the formation ofopenings 115, 117 with a reduced likelihood of either tearing or rippingthe septum 150.

In another embodiment, the septum 150 is composed of an elastomericmembrane that is either adhesively bonded with the rear cover 54 or,when the rear cover 54 is integrally formed, with the rear cover 54 byan overmolding process. In yet another embodiment, the septum 150 may beformed from a material having a durometer of about 30 Shore A, asmeasured by the ASTM D2240 type A scale, and a thickness in a range ofabout 25 mils to about 35 mils. These combinations of durometer (i.e.,the material's resistance to permanent indentation) and thicknesses isbelieved adequate to impart tear and rip resistance when the tips 114,116 pierce the septum 150. Other representative materials for septum 150include, but are not limited to, thermoplastic elastomers (TPEs), suchas the DYNAFLEX® family of TPE compounds commercially available from GLSCorporation (McHenry, Ill.).

While the invention has been illustrated by a description of variousembodiments and while these embodiments have been described inconsiderable detail, it is not the intention of the applicant torestrict or in any way limit the scope of the appended claims to suchdetail. Additional advantages and modifications will readily appear tothose skilled in the art. Thus, the invention in its broader aspects istherefore not limited to the specific details, representative apparatusand method, and illustrative example shown and described. Accordingly,departures may be made from such details without departing from thespirit or scope of applicant's general inventive concept.

1. An apparatus for treating tissue located beneath a skin surface withhigh frequency energy, the apparatus comprising: a handpiece; atreatment tip configured to be removably coupled with the handpiece, thetreatment tip including an electrode configured to deliver the highfrequency energy to a region of the tissue, a channel for circulatingheat transfer fluid proximate to the electrode, and an inlet passage tothe channel; a first conduit inside the handpiece, the first conduitincluding a tubular sidewall and a lumen inside the tubular sidewall,the lumen configured to be coupled with the inlet passage fortransferring the heat transfer fluid from the handpiece to the inletpassage of the treatment tip; and a septum covering the inlet passage,the septum configured to be pierced by the first conduit to define afirst opening for coupling the first conduit with the inlet passage whenthe treatment tip is coupled to the handpiece and to substantially sealthe first opening when the treatment tip is removed from the handpieceto decouple the first conduit from the inlet passage.
 2. The apparatusof claim 1 wherein the septum is a membrane composed of an elastomericmaterial.
 3. The apparatus of claim 1 wherein the septum is a membranecomposed of a thermoplastic elastomer.
 4. The apparatus of claim 1wherein the septum is a membrane composed of a material having adurometer of about 30 Shore A measured by the ASTM D2240 type A scaleand a thickness in a range of about 25 mils to about 35 mils.
 5. Theapparatus of claim 1 wherein the septum includes a starter openingextending through the septum at a predicted location of the firstopening, the starter opening configured to initiate formation of thefirst opening without tearing the septum.
 6. The apparatus of claim 1wherein the treatment tip includes an outlet passage from the channel,and further comprising: a second conduit inside the handpiece, thesecond conduit including a lumen configured to be coupled with theoutlet passage for transferring the heat transfer fluid from the inletpassage of the treatment tip to the handpiece.
 7. The apparatus of claim6 wherein the septum covers the outlet passage, and the septum isconfigured to be pierced by the second conduit to define a secondopening to the outlet passage when the treatment tip is coupled to thehandpiece and to substantially seal the second opening when thetreatment tip is removed from the handpiece.
 8. The apparatus of claim 1wherein the septum is configured to completely seal the first openingwhen the treatment tip is removed from the handpiece.
 9. The apparatusof claim 1 further comprising: a second conduit inside the handpiece,the second conduit coupled in fluid communication with the firstconduit, and the second conduit having a smaller shear modulus than thefirst conduit; and a flow control valve inside the handpiece, the flowcontrol valve coupled with the second conduit, and the flow controlvalve configured to occlude the lumen of the second conduit, when thetreatment tip is removed from the handpiece, for reducing leakage of theheat transfer fluid from the first conduit.
 10. The apparatus of claim 9wherein the flow control valve is a pinch valve configured to apply acompressive force to the tubular sidewall of the second conduit tocontrol a flow of the heat transfer fluid through the lumen of the firstconduit.
 11. The apparatus of claim 10 wherein the tubular sidewall ofthe second conduit is composed of a material with sufficient flexibilityto deform to at least partially reduce a cross-sectional area of thelumen, when the compressive force is applied by the pinch valve, andsupply the leakage reduction from the first conduit.
 12. A method ofoperating a tissue treatment apparatus to treat tissue located beneath askin surface with high frequency energy delivered from an electrode, themethod comprising: attaching a treatment tip carrying the electrode to ahandpiece to establish a fluid connection between a lumen of a firstconduit in the handpiece and an inlet passage in the treatment tip;piercing a septum with the first conduit, when attaching the treatmenttip to the handpiece to establish the fluid connection, to define afirst opening permitting the first conduit to be coupled in fluidcommunication with the inlet passage; transferring heat transfer fluidthrough the lumen of the first conduit to the treatment tip; anddelivering the high frequency energy from the electrode to a region ofthe tissue to perform a tissue treatment.
 13. The method of claim 12further comprising: after delivering the high frequency energy, removingthe treatment tip from the handpiece; and when the treatment tip isremoved from the handpiece, resiliently closing the first opening in theseptum.
 14. The method of claim 12 wherein delivering the high frequencyenergy further comprises: transmitting the high frequency energy fromthe electrode through a dielectric substrate by capacitive coupling withthe region of the tissue.
 15. The method of claim 12 further comprising:when the treatment tip is attached to the handpiece, establishing afluid connection between a lumen of a second conduit in the handpieceand an outlet passage in the treatment tip; piercing the septum with thefirst conduit, when attaching the treatment tip to the handpiece, todefine a second opening permitting the second conduit to be coupled influid communication with the outlet passage; and transferring the heattransfer fluid through the lumen of the second conduit from thetreatment tip to the handpiece.
 16. The method of claim 15 furthercomprising: removing the treatment tip from the handpiece so that theeach of the first and second conduits has an open end; and when thetreatment tip is removed from the handpiece, at least partiallyoccluding the lumen of the first conduit and the lumen of the secondconduit so that a negligible amount of the heat transfer fluid leaksfrom the open end of the first conduit and the open end of the secondconduit.
 17. The method of claim 16 wherein the occlusion of the lumensof the first and second conduits occurs concurrently.
 18. The method ofclaim 12 further comprising: removing the treatment tip from thehandpiece so that the first conduit has an open end; and when thetreatment tip is removed from the handpiece, at least partiallyoccluding the lumen of the first conduit so that a negligible amount ofthe heat transfer fluid leaks from the open end of the first conduit.